Jenkins setup:
Jenkins: 2.504.1
OS: Linux - 6.1.0-31-amd64
Java: 21.0.7 - Oracle Corporation (Java HotSpot™ 64-Bit Server VM)ace-editor:1.1
ansicolor:1.0.6
ant:513.vde9e7b_a_0da_0f
antisamy-markup-formatter:173.v680e3a_b_69ff3
apache-httpcomponents-client-4-api:4.5.14-269.vfa_2321039a_83
asm-api:9.8-135.vb_2239d08ee90
bootstrap4-api:4.6.0-6
bootstrap5-api:5.3.5-1
bouncycastle-api:2.30.1.80-256.vf98926042a_9b_
branch-api:2.1217.v43d8b_b_d8b_2c7
build-name-setter:2.5.0
build-timeout:1.38
build-user-vars-plugin:195.v8c35f9d5c3dc
caffeine-api:3.2.0-166.v72a_6d74b_870f
checks-api:370.vb_61a_c57328f3
cloudbees-folder:6.1012.v79a_86a_1ea_c1f
command-launcher:123.v37cfdc92ef67
commons-compress-api:1.27.1-3
commons-lang3-api:3.17.0-87.v5cf526e63b_8b_
commons-text-api:1.13.0-153.v91dcd89e2a_22
conditional-buildstep:1.5.0
configuration-as-code:1967.va_968e15fd05b_
credentials:1415.v831096eb_5534
credentials-binding:687.v619cb_15e923f
data-tables-api:2.2.2-1
description-setter:264.v1957f215dcd5
display-url-api:2.209.v582ed814ff2f
durable-task:587.v84b_877235b_45
echarts-api:5.6.0-4
eddsa-api:0.3.0.1-19.vc432d923e5ee
editable-choice:71.v02a291ebbe45
email-ext:1876.v28d8d38315b_d
envinject:2.926.v69c9b_3896a_96
envinject-api:1.235.va_14c74f8f487
font-awesome-api:6.7.2-1
gearman-plugin:0.8.0
generic-webhook-trigger:2.3.1
gerrit-trigger:2.42.0
git:5.7.0
git-client:6.1.3
git-parameter:439.vb_0e46ca_14534
git-server:137.ve0060b_432302
github:1.43.0
github-api:1.321-488.v9b_c0da_9533f8
github-branch-source:1815.v9152b_2ff7a_1b_
github-oauth:651.v135e939e8b_60
gitlab-api:5.6.0-100.v83f8f4b_f1129
gitlab-oauth:1.22
gradle:2.14.1
gson-api:2.13.1-139.v4569c2ef303f
handlebars:3.0.8
instance-identity:203.v15e81a_1b_7a_38
ionicons-api:88.va_4187cb_eddf1
jackson2-api:2.18.3-402.v74c4eb_f122b_2
jakarta-activation-api:2.1.3-2
jakarta-mail-api:2.1.3-2
javadoc:327.vdfe586651ee0
javax-activation-api:1.2.0-8
javax-mail-api:1.6.2-11
jaxb:2.3.9-133.vb_ec76a_73f706
jdk-tool:83.v417146707a_3d
jersey2-api:2.45-154.v4ded3dc34f81
jjwt-api:0.11.5-120.v0268cf544b_89
jnr-posix-api:3.1.20-138.vdb_9db_a_39182f
job-dsl:1.92
joda-time-api:2.14.0-127.v7d9da_295a_d51
jquery:1.12.4-3
jquery3-api:3.7.1-3
jsch:0.2.16-95.v3eecb_55fa_b_78
json-api:20250107-125.v28b_a_ffa_eb_f01
json-path-api:2.9.0-148.v22a_7ffe323ce
jsoup:1.20.1-46.ve5f1416988c2
junit:1322.v1556dc1c59a_f
ldap:780.vcb_33c9a_e4332
lockable-resources:1349.v8b_ccb_c5487f7
mailer:489.vd4b_25144138f
matrix-auth:3.2.6
matrix-project:849.v0cd64ed7e531
maven-plugin:3.26
mina-sshd-api-common:2.15.0-161.vb_200831a_c15b_
mina-sshd-api-core:2.15.0-161.vb_200831a_c15b_
momentjs:1.1.1
monitoring:2.5.0
nodelabelparameter:759.vb_b_e95db_f3251
okhttp-api:4.11.0-189.v976fa_d3379d6
oss-symbols-api:324.v432cce4172ca_
pam-auth:1.12
parameterized-trigger:859.vb_e3907a_07a_16
pipeline-build-step:567.vea_ce550ece97
pipeline-github:2.8-162.382498405fdc
pipeline-github-lib:65.v203688e7727e
pipeline-graph-analysis:235.vb_a_a_36b_f248c2
pipeline-groovy-lib:752.vdddedf804e72
pipeline-input-step:517.vf8e782ee645c
pipeline-milestone-step:134.vdf60d179845f
pipeline-model-api:2.2255.v56a_15e805f12
pipeline-model-definition:2.2255.v56a_15e805f12
pipeline-model-extensions:2.2255.v56a_15e805f12
pipeline-rest-api:2.38
pipeline-stage-step:322.vecffa_99f371c
pipeline-stage-tags-metadata:2.2255.v56a_15e805f12
pipeline-stage-view:2.38
pipeline-utility-steps:2.19.0
plain-credentials:195.vb_906e9073dee
plugin-util-api:6.1.0
popper-api:1.16.1-3
popper2-api:2.11.6-5
postbuild-task:72.v75dc459e4747
prism-api:1.30.0-1
rebuild:338.va_0a_b_50e29397
resource-disposer:0.25
robot:6.0.0
role-strategy:756.v978cb_392eb_d3
run-condition:243.v3c3f94e46a_8b_
scm-api:704.v3ce5c542825a_
script-security:1373.vb_b_4a_a_c26fa_00
sectioned-view:1.30
shiningpanda:0.24
snakeyaml-api:2.3-125.v4d77857a_b_402
ssh-credentials:355.v9b_e5b_cde5003
ssh-slaves:3.1031.v72c6b_883b_869
sshd:3.353.v2b_d33c46e970
startup-trigger-plugin:2.9.4
structs:343.vdcf37b_a_c81d5
throttle-concurrents:2.16
timestamper:1.28
token-macro:444.v52de7e9c573d
trilead-api:2.209.v0e69b_c43c245
uno-choice:2.8.8
variant:70.va_d9f17f859e0
workflow-aggregator:608.v67378e9d3db_1
workflow-api:1371.ve334280b_d611
workflow-basic-steps:1079.vce64b_a_929c5a_
workflow-cps:4106.v7a_8a_8176d450
workflow-cps-global-lib:615.vb_b_0664a_b_19f3
workflow-durable-task-step:1405.v1fcd4a_d00096
workflow-job:1520.v56d65e3b_4566
workflow-multibranch:806.vb_b_688f609ee9
workflow-scm-step:437.v05a_f66b_e5ef8
workflow-step-api:700.v6e45cb_a_5a_a_21
workflow-support:968.v8f17397e87b_8
ws-cleanup:0.48
After update my jenkins instane from version:
Jenkins: 2.346.3
OS: Linux - 4.19.0-21-cloud-amd64
Java: 11.0.16 - Debian (OpenJDK 64-Bit Server VM)ace-editor:1.1
ansicolor:1.0.2
ant:481.v7b_09e538fcca
antisamy-markup-formatter:159.v25b_c67cd35fb_
apache-httpcomponents-client-4-api:4.5.13-138.v4e7d9a_7b_a_e61
bootstrap4-api:4.6.0-5
bootstrap5-api:5.2.1-3
bouncycastle-api:2.27
branch-api:2.1071.v1a_188a_562481
build-name-setter:2.2.0
build-timeout:1.24
build-user-vars-plugin:1.9
caffeine-api:2.9.3-65.v6a_47d0f4d1fe
checks-api:1.8.1
cloudbees-folder:6.740.ve4f4ffa_dea_54
command-launcher:90.v669d7ccb_7c31
commons-lang3-api:3.12.0-36.vd97de6465d5b_
commons-text-api:1.10.0-27.vb_fa_3896786a_7
conditional-buildstep:1.4.2
configuration-as-code:1569.vb_72405b_80249
credentials:1143.vb_e8b_b_ceee347
credentials-binding:523.525.vb_72269281873
description-setter:1.10
display-url-api:2.3.6
durable-task:507.v050055d0cb_dd
echarts-api:5.4.0-1
editable-choice:60.v68c6aa7fa01e
email-ext:2.92
envinject:2.901.v0038b_6471582
envinject-api:1.199.v3ce31253ed13
font-awesome-api:6.2.1-1
gearman-plugin:0.6.3.78b157a
generic-webhook-trigger:1.86.3
gerrit-trigger:2.36.0
git:4.14.3
git-client:3.13.1
git-parameter:0.9.18
git-server:1.11
github:1.34.5
github-api:1.303-400.v35c2d8258028
github-branch-source:1696.v3a_7603564d04
github-oauth:0.39
gitlab-api:5.1.0-84.v491924123a_f7
gitlab-oauth:1.16
gradle:2.7
handlebars:3.0.8
ionicons-api:31.v4757b_6987003
jackson2-api:2.14.2-319.v37853346a_229
jakarta-activation-api:2.0.1-2
jakarta-mail-api:2.0.1-2
javadoc:226.v71211feb_e7e9
javax-activation-api:1.2.0-5
javax-mail-api:1.6.2-8
jaxb:2.3.7-1
jdk-tool:63.v62d2fd4b_4793
jersey2-api:2.37-1
jjwt-api:0.11.5-77.v646c772fddb_0
jnr-posix-api:3.1.16-1
job-dsl:1.81.1
jquery:1.12.4-1
jquery3-api:3.6.1-2
jsch:0.2.8-65.v052c39de79b_2
junit:1166.1168.vd6b_8042a_06de
ldap:659.v8ca_b_a_fe79fa_d
lockable-resources:2.18
mailer:435.438.v5b_81173f5b_a_1
matrix-auth:3.1.5
matrix-project:772.v494f19991984
maven-plugin:3.22
mina-sshd-api-common:2.9.2-50.va_0e1f42659a_a
mina-sshd-api-core:2.9.2-50.va_0e1f42659a_a
momentjs:1.1.1
monitoring:1.94.1
nodelabelparameter:1.11.0
okhttp-api:4.9.3-108.v0feda04578cf
pam-auth:1.10
parameterized-trigger:2.45
pipeline-build-step:488.v8993df156e8d
pipeline-github:2.8-141.7e985db66f30
pipeline-github-lib:38.v445716ea_edda_
pipeline-graph-analysis:202.va_d268e64deb_3
pipeline-groovy-lib:629.vb_5627b_ee2104
pipeline-input-step:466.v6d0a_5df34f81
pipeline-milestone-step:111.v449306f708b_7
pipeline-model-api:2.2121.vd87fb_6536d1e
pipeline-model-definition:2.2121.vd87fb_6536d1e
pipeline-model-extensions:2.2121.vd87fb_6536d1e
pipeline-rest-api:2.28
pipeline-stage-step:305.ve96d0205c1c6
pipeline-stage-tags-metadata:2.2121.vd87fb_6536d1e
pipeline-stage-view:2.28
pipeline-utility-steps:2.15.0
plain-credentials:143.v1b_df8b_d3b_e48
plugin-util-api:2.20.0
popper-api:1.16.1-3
popper2-api:2.11.6-2
postbuild-task:1.9
rebuild:1.34
resource-disposer:0.20
robot:3.3.0
role-strategy:587.588.v850a_20a_30162
run-condition:1.5
scm-api:631.v9143df5b_e4a_a
script-security:1229.v4880b_b_e905a_6
sectioned-view:1.25
shiningpanda:0.24
snakeyaml-api:1.33-90.v80dcb_3814d35
ssh-credentials:305.v8f4381501156
ssh-slaves:1.834.v622da_57f702c
sshd:3.242.va_db_9da_b_26a_c3
startup-trigger-plugin:2.9.3
structs:324.va_f5d6774f3a_d
throttle-concurrents:2.10
timestamper:1.21
token-macro:321.vd7cc1f2a_52c8
trilead-api:1.67.vc3938a_35172f
uno-choice:2.6.5
variant:59.vf075fe829ccb
workflow-aggregator:596.v8c21c963d92d
workflow-api:1200.v8005c684b_a_c6
workflow-basic-steps:994.vd57e3ca_46d24
workflow-cps:3536.vb_8a_6628079d5
workflow-cps-global-lib:588.v576c103a_ff86
workflow-durable-task-step:1217.v38306d8fa_b_5c
workflow-job:1207.1209.v69351208a_5a_7
workflow-multibranch:716.vc692a_e52371b_
workflow-scm-step:408.v7d5b_135a_b_d49
workflow-step-api:639.v6eca_cd8c04a_a_
workflow-support:839.v35e2736cfd5c
ws-cleanup:0.43
I lost functionality when after jenkins reload (safeRestart/systemctl restart/by jcasc plugin - Reload existing configuration) all previously-set offline agents stay offline. On older jenkins version: Jenkins: 2.346.3 it was work that way. Offline nodes was offline until manual setting it online again. On newer version: Jenkins: 2.504.1 agents all the time(after restart/config reload) becomes online. It is bug or it was a bug before?